Not true about domestic ones having to be vented to outdoors. We've a Maytag over the range model that did not require venting, which was great as it is on the wall to our attached garage. I installed it myself to replace an interior venting range hood that crapped out.
The Dometic microwave/convection in our Montana is vented to outside (which I prefer), but when it dies, I'll be getting something better (domestic or otherwise).
2010 Montana 3665RE, wet bolts, etc.
2006 Ford F350 Diesel Dually, air bags, Softopper, Aeroshild, etc.